Pencil and process of making the same



Amigo n 0' 119m.

' LEMRW L. W. BUGBEE PENCIL AND PROCESS OF MAKING THE SAME Filed Jan. 18 1 924 Tllli. L

INVENTOR. Z yaw/v 14 Emma:

A TTORNEYE atented Aug. l2, lgfifi LUCIAN W. JB'UGBEE, 0F INDIANAPOLIS, INDIANA.

PENCIL AND PROCESS OF MAKING THE SAME.

Application filed January is, 1924. Serial No. 687,031.

To aZZ whom" it may concern."

Be it known that L'LUoIAN W. Bunsen, a citizen of the United States, and a resident of Indianapolis, county of Marion and State of Indiana, have invented a certain new and useful Pencil and Process of Making the Same, and do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, in which like numerals refer to like parts.

One of the objects of this invention is the provision of a pencil which will mark black like india ink instead of the grey plumbago mark of ordinary lead pencils, and also making the mark water proof and indelible;

One feature of the invention consists in making a pencil that will mark black like india ink rather than the grey plumbago mark of the ordinary lead pencil by mixing wood dust or other carbonaceous material with clay and after the extrusion of the leads, heating them in a closed crucible or inert gas so that the wood dust will be charred and become charcoal. Hence, a lead pencil made by this process when completed will consist of clay and charcoal intermixed and it will make very black lines much like those made by india ink.

Another feature of the invention consists in filling the pores of the leads after they have been treated as above specified with a filler or substance that will act as a varnish, rendering the writing waterproof and at the same time strengthening the lead.

The full nature of the invention will be understood from the accompanying draw-v ings and the following description and claims: I

lin the drawings, Figure l is a plan View of a metal case pencil. Fig. 2 is a plan view of a lead after it has been extruded. Fig. 3

" is a partof Fig. 2, greatly enlarged and showing the mixture of clay and wood dust.

Fig. 4: is the same as Fig. 3 after-the wood dust is charred and become charcoal. Fig.

5 is the same as Fig. 4 with a filler or varr nish. Fig. 6 is a section of the end of Fig. 1 greatly enlarged.

lin thefirst place a plastic mass is formed.

of clay 8 and fine wood dust 9 which have been thoroughly intermixed with sufficient water to form them into a plastic mass. Preferably two parts of wood dust and one part of clay are used, but the invention is not limited to said proportions as they may be varied according to the hardness desired.

Then the material is placed in a suitable extruding device, which is well known in the lead pencil art, and leads 10, as shown in Fig. 2, are extruded or produced. These leads when first formed consist only of the wood dust and clay intermixed, as shown in the enlarged drawing in Fi 3.

After drying the leads such as shown in Fig. 2, they are placed in a closed container, not shown, and heated to a red heat or heated sufficiently to change the wood dust to charcoal and also to harden the clay, as shown in Fig. 4.

The process so far described forms one type of pencil, in which the lead consists of hardened clay and charcoal intermixed and which will make jet black marks, as black as india ink, and strikingly blacker than the griey plurnbago marks of ordinarylead penc1 s.

These leads are somewhat like the ordinary lead pencil leads with the exception that the carbon in these leads is in the amorphous form, that is to say in the form of charcoal instead of graphite, and the carbon in these leads is also in a highly porous condition.

It is preferable, however, to carry the process a step further by way of filling the pores of the material, the porous charcoal and the clay, with a substance 11 that will act as a varnish and also render the writing waterproof and at the same time it will strengthen the lead. This varnish or wax will also form an elastic coating surrounding the lead which will enable it to snugly fit the bore of pencil holders of the type shown at 15, as seen in Fig. 1. In other words, the yielding coating will cause i a tight fit of the lead in the holder.

This filling is preferably stearic acld, but it may be beeswax, paraffin or waxes of like nature or it may be any of the resins softened to the proper degree, or a gelatin solution, or it may be a drying or oxldlzmg the .clay an char the carbonaceous material oil, such as linseed oil mixed with the proper drier. The leads may also be coated with an outer protecting coat of shellac or other suitable varnish to protect oxidizing excepting when worn away on the end when in use and to strengthen the lead. In this case the act of writing will expose new unoxidized material in the lead, which, as it is transferred to the paper, will quickly oxidize and protect the pigment.

The invention is not necessarily confined I to any given filler of the general nature above stated, but the filler must be such as to fill the pores and strengthen the lead against breaking while'in use and protect the pigment and make the writing or drawing waterproof and permanent or indelible. The clay in these lead pencils operates to rub or burnish the coloring matter firmly into the fibers of the paper so as to make the same indelible and the waxcooperates therewith in making the writing waterproof.

It isdesirable to mix with the clay and wood dust or other carbonaceous material in forming the lead, some gelatin, glue, dextrine or other similar material, in order to strengthen the leads so they can be handled without breaking before firing. The above added material also assists in the extrusion process as it acts as a lubricant between-the clay particles while under pressure in extruding. The above added material is carbonaceous so that they willbe charred by the fire along with the wood dust or other carbonaceous material.

Also it is desirable that the clay employed be a mixture of burnt and unburnt clay so as to prevent toogreat shrinking of %he material and twisting out of shape while ring.

Also I can use an almost unlimited number of chemicals'with stearic acid or other vehicle above specified to obtain different colors, either by chemical action or exposure to light..

The invention claimed is:

1. The process of making a pencil, which process includes forming a lead composed of clay and carbonaceous material intermixed and heatin the lead sufiiciently to harden and convert it into .charcoal or the like.

2. The process of making a pencil, which process includes forming a lastic mass of clay and wood dust, extru ing theasame into leads, and heating the leads sufiicient to harden the clay and char the wood dust and convert it into charcoal.

3. Theprocess of making a pencil, which process includes forming a plastic mass composed substantiallyo ne part clay and two parts of wood dust, extruding the same into leads, and heating the leads. sufiicient 4. The process of making a pencil, which process includes forming a lead composed of clay and carbonaceous material intermixed, heating the lead sufiiciently to harden the clay and char the carbonaceous material and convert it into charcoal or the like, and saturating thesame with a fluid as desired to fill the pores thereof.

5. The process of making a pencil, which process includes forming a lead composed of clay and carbonaceous material intermixed, heating the lead suificiently to harden the clay and char the carbonaceous material and convert it into charcoal or the like, and saturating the same in wax while in fluid form for filling the pores and coating the same.

6. The process of making a pencil, which process includes forming a plastic mass of clay and wood dust, extruding the same into leads, heating the leads sufficient to harden the clay and char the wood dust and convert it into charcoal, and filling the pores thereof with stearic acid and thelike.

7. The process of making a pencil, which process includes forming a plastic mass of clay and wood dust, extruding the same into leads, heating the leads suflicient to harden the clay and char the Wood dust and convert it into charcoal, and saturating the same in a wax while in fluid form so as to fill the pores and coat the same.

8. The process of making a pencil, which process includes forming a lead composed of clay and a carbonaceous material including some gelatinous material intermixed, and heating the lead sufiicient to harden the cla and char the carbonaceous material an convert it into charcoal and the like.

9. The process of making a pencil, which process includes forming a lead composed of burnt and unburnt clay and carbonaceous material intermixed, and heatin the lead sufiiciently'to harden the clay an char the carbonaceous material and convert it into charcoal or the like.

10. The process of making a pencil, which process includes forming a lead composed of clay and carbonaceous material 1ntermixed," heating material and convert it into charcoal and the like, and saturating the same in wax the lead suificiently to' harden the clay and char the carbonaceous while in fluid form, and suitable coloring i material.

11. A pencil having lead composed of hardelned clay and charred materialintermixe 12. A pencil having lead composed of substantially one part hardened .clay and two parts charcoal intermixed.

13. A pencil having lead composed of 5 hardened clay and moaaoe hardened clay and charred material intermixed and the pores thereof filled with a wax-like material.

14:. A pencil having lead composed of charred material intermixed and the pores thereof filled with a wax-like material, and suitable coloring material.

15. A pencil havinglead composed of substantially one part of hardened clay and la two parts of charcoal intermixed and the pores thereof filled with stearic acid.

16., A pencil having material for marking, and a coating of yieldingmaterial surrounding said marking material,

In witness whereof I have hereunto afixed my signature.

LUCIAN W. JBUGBEE. 

